Thermostatically operated electric switch



Dec. 4, 1934. G, W HART THERMOSTATICALLY OPERATED ELECTRIC SWITCH Filed Nov. 14, 1931 2 SheeS-Sheel l mill/@L gmenoz em'ld h/ Han', kammen y Thomas Hewedam WA rit/zur banni/manu? Md/*s dbbotmq Dec. 4, 1934. G. w. HART 1,982,955

THERMOSTATICALLY OPERATED ELECTRIC SWITCH Filed Nov. 14, 1931 2 sheets-sheet 2 Gera'ld 14,/ Hareceaed b 'Tha/:zas Hewes and adjusting the device Patented' Dec. 4, i934 UNITED STATES Latinas PATENT OFFICE 1,982,955 THERMOSTATIGALLY OPERATED ELECTRIC SWITC Gerald W. Hart, deceased, late of Hartford,

by Thomas Hewes, Arthur Countryman, mnistrators Application November 14, 1931, Serial No.

` (ci. eco-13s) 9 Claims.

apparatus is tion.

The aim of the present invention is to provide an improved device having a .thermostatic element and a switch operated thereby, means for so that the thermostatic element will make and break the switch at any desired temperature within a given range of operation, and means for indicating, at all times, the temperature of the apparatus or chamber the heat of which is to be controlled; the setting means being adJustable at all times and irreu accuracy with which making compilationsyand which is so Aarranged and` constructed that the temperature of the chamber to be controlled and the setting of the device for operation at any given temperature may be clearly observed at all times.

A still further aim of the invention is to provide a thermostatically operated indicator and switch which is characterized by its simplicity in construction, its compactness in arrangement, and its effectiveness in operation.

Other objects will be in part obvious, and in part pointed out more in detail hereinafter.

The invention accordingly consists in the features of construction, combination of elements, and arrangement of parts which will be exemplified in the construction hereinafter set forth and the scope of the application of which will be indicated in the appended claims.

In the accompanying drawings, wherein is shown one of the embodiments which the present invention may take,

Fig. 1 is a front elevational view of the device with the cover removed;

Fig. 2 is a sectional view taken longitudinally and centrally through the device, this view being taken substantially on line 22 of Fig. 1;

Fig. 3 is a view similar to Fig. 1 but showingy only.

Conn.,

Farmington, Conn., and W.

Jr., Hartford, Conn., ad

the mercury switch tilted to a position where the current is broken; I l

Fig, 4 is atop View of the casing and shows the scale with which is associated two pointers;

Fig. 5 is a perspective ber; and

Fig. 6 is a front view of the clutch, parts being broken away for purposes of clearness.

Referring to the drawings in detail, the is shown, for

by a screw 16. The forward end of the coil is connected to the rear end of a shaft 17 journalled for rotary movement in partitions 18 so far described is shown by way of illustration The switch is operated by through the shaft 17, and is of the Well known mercury the thermostatic coil here shown as being type which consists e 19 having' a pair of terminals or contacts 20 and a circuit closing member in the form of a body or globule or mercury 21. The mercury switch is carried by a holder 22, preferably formed of sheet metal and having two pairs of spring fingers 23 and 24 between which the tube is held. One of the lingers 24 is relatively long, and is adapted to engage against a stud 25 projecting rearwardly from the cover. In the present illustrated disclosure, the mercury switch is pivoted for relatively free rocking movement on, and relative to, the shaft 17. As shown in Fig. 2, the shaft extends through the opposite sides of the holder, and the holder is held against axial movement on the shaft by a split washer 26. The pivotal point of the mercury switch is off center, that is, it is located to one side of the center of mass of the switch and holder so that normallythe tube, under the force of gravity, will assume the horizontal position shown in Fig. 1 and in which` position the long finger 24 engages the stud 25. It is not essential that the axis about which the mercury switch rocks be coincident with the vaxis of the shaft 17, the present arrangement being disclosed byl way of illustration only. The numeral 27 desigview of the setting mem- D .20 trated disclosure, there is.

2 Y 1,982,955 nates a suitable insulating block having posts 28 to which the contacts 20 are respectively connected by flexible wires 29, as is usual in switches of this type.

In accordance with the present invention, there is provided a graduated scale which is rocked or turned by the thermostatic element as the temperature of the latter changes; a stationary pointer associated with that `scale for 1o indicating the temperature within to be controlled; and means between 1'1 and the mercury switch through which the mercury switch is rocked by the thermostatic coil, this means ,the point at which the current broken, and this` means having a setting member cooperating with the scale for indicating on the scale at all times the temperature at which the device is set to operate. In the present illusaihxed to the shaft within the casing a hub or collar 30 to which is fixed a sheet metal disk 31 having a cylindrical skirt 32 on the periphery of which is mounted a scale 33, the latter having, as mostI clearly shown in Fig. 4, suitable graduations for indicating degrees of temperature. The member may be operating member 36 relative to the driving disk 44, the setting member shown in Fig. 5 is provided. This setting member 37 includes a part two prongs 51; an arm 52 having a pointer 38 and a nger piece 54; and a flanged bushing 55 extending through the arm and part and connecting the same together. The bushing has a through opening which accommodates the shaft 17. bushing is adapted to be turned relative to this shaft. The prongs 5l extend through the slot 43 in the cage and are adapted to respectively engage the balls 45. The pointer 38 extends over rI fhe operation of the device will be clear from the foregoing description, taken in connection With the following brief explanation. The mercury switch, due to the fact that it is pivoted off center, will normally zontal position shown in Fig. 1 where the long arm 24 engages the pin or stud 25 and the mercury closes the circuit between the terminals 20. To adjust the device so that the circuit will be broken at' the desired temperature, it is merely necessary to move the setting lever 37 until the pointer 38 thereof is brought into registry with that indication mark of the scale corresponding adjustably fixed 130 the Shaft by a Set SCIelY 342-, to the desired temperature at which the device The numeral 35 designates 2 Stationary lmmte Vis to operate. 1i, in setting the lever, it is moved which, in the present instance, iS xedly mllntto the right, referring to the drawings, say from 30 ed on the back plate. This pointer extends over three hundred degrees to four the scale 33 and indicates thereon the temperaas indicated bythe Scaley the 1efthand prong 51 ture at any time prevailing within the Chamber rst moves the left-hand ball to the right and out to be controlled. oi clutching position and then the right-hand l aSSOCla'ffmg @he prong comes into engagement with the right-hand the switch includes @in Opetmg end of the slot 43, whereupon the cage will be member form Of im afm 0f adjusted with respect to the disk 44. when meer 3e which is adjustable relative to the shaft the leve-f is set to the left, it is the righi-hand. 17- .The adl'llstable and dsengageable Comes' prong which moves the right-hand ball from ention between the operating member andthe shaft goood posltlon ood the left hand prong which is in the form of a ball clutch, and the adiustment engages the lot hand ond of the slot 43* when may be eiected by. a setting lever 37 having 9 the setting memberV is released, the spring 46 DOmter 33 COODefaimg .Wlth the Scale 3- forces both of the balls to their normal positions Referring more p atlculm'ly the luustra'twe f so that each forms a driving connection between embOdmeni' Shown m th? da'wmgs the finger or the disk 44 and the cage. lt is, of course, obvious arm 36 iS filied t0, 01 Carried by a' clutch member that, when the clutch member or cage is adjusted 01 Cage haVlIlg a fom'f Wan 39 a Tear Wan 40 and relative to the disk, the'operating memberor arn e. peripheral wall 4l. y, The front wall has an open- 36 ls correspondingly adjusted andy lo ls also adl lng 42 through which the Shaft 17 extends. The to the holder for the mercllrl iront wall also ha an arcuate opening 4,3,the purswitch. It is also lmoortant to noto that thf 5o POSQO which Wm be heltnafdescnbed- The driving connection between the shaft and th pomo 44 the edge operating member 36 may be adjusted at any tim 0f Whlch 1s Straddled by the from apd rear Walls and irrespective of the temperature and conditie 0f the Cagefrom Flf' and the indicated setting of the opei 115k 01 Clutch t is not disturbed during the opere 0f the Shaft, Whlle the Deflphefal Wall 41 0f the non of the device because the scale 33 turns wu other clutch member is eccentric; in other words, the Shaft 17 and the setting member also tur] there is provided between the disk and the pewith that shaft during norma'l operation df tl Tphefal'wu 41 a Space which gradually tapers device. The fixed pointer 35 indicates on tl down in height or radial distance to either side scale 33 the temperature Wllhln the Chamber oi a central point. Within this. space are two be controlled Assuming that the device h spherical balls 45 between which is a compression been sot to operate at vo hundred degrees' Spriig 46 normally llfgmg the bans @mit the temperature of the oven or other chaml will be understood that, when the balls are in the to be conlrollod rises, the Shaft lq and the Glut normal position shown in Fig. 6, the cage or driven member 44 Wlll be rotated @untel-clockwise a e5 Clutch member having the Operating element 36 the disk win tend. to crowd the left-hand 1:

turn the as Shaft is turned more against, the peripheral by the thermostatic coil and irrespective as to the cage and thus cause the Cage t0 rotate W Which direction. the Shaft is turned? that' is t0 Sayl the disk in a counterclockwise direction, and tl if the shaft is turned COlIltGIClGCkWSe. the operating member 36 is slowly raised towa i0 Fg- 6, the left-hand the bottom of the switch holder 22. lJl/hen nection between the disk 44 and the cage and, five hundred degrees temperature is reached,l when the disk is rotated in the opposite direction, operating arm will rock the switch to the posi` the right-hand ball serves as a driving connection. shown in Fig. 3 and in which position the curi For the purpose oi disengaging the clutch and has been broken. The temperature of the c i5 adjusting the driven clutch member having the will now fall, and the thermostatic elemen hundred degrees 1 above description or shown in the will turn the shaft in a clockwise direction with the result that the disk 44 will turn the cage through the right-hand ball 45 in a direction to lower thefoperating member 36, thus permitting the switch to assume its normal position shown in Fig. 1 and thus again make the circuit.

As many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the language used in the following claims is intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention which, as a matterof language, might be said to fall therebetween.

What is claimed is:

l. In a thermostatically operated switch, a switch, thermostatic means, a scale adapted to be turned by said thermostatic means, an operating member between said thermostatic means and switch and adapted to be turned by said thermostatic means in unison with said scale, an adjustable clutch between said operating member and thermostatic means, and means for setting said operating member relative to said thermostatic means and having a pointer cooperating with said scale.

2. In a thermostatically operated switch, a switch comprising a pivoted mercury tube, thermostatic means, a scale associated with, so as to be rotated by, said thermostatic means, an operating member adapted to be turned by said- 'thermostatic means and to engage said switch, an adjustable clutch between said operating member and thermostatic means whereby said operating member may be adjusted relative to said switch, and a pointer cooperating with said scale, adjustable with said operating member,

and adapted to be turned in unison therewithY by said thermostatic means.

3. In a thermostatically operatedl switch, 'a

pivoted mercury tube, thermostatic means, a scale associated with, so as to be turned by, said thermostatic means, an operating member adapted to be turned by said thermostatic means and adjustable relative to said switch, adjustable clutch means between said operating member and thermostatic means, and a setting member for controlling saidclutch means and having a pointer cooperating with switch comprising a said scale and adapted to be turned by said thermostatic means.

4. In a thermostatically operated switch, a

I switch `comprising a pivoted mercury tube, thermostatic means, an operating member adapted to be turned by said thermostatic means and through which said thermostatic means is adapted to tilt said switch, a double acting adjustable clutch between said operating member and thermostatic means, and a pointer movable'and adjustable with said operating member and co,- operating with said scale. l

5. In a thermostatically operated switch, a switch comprising a pivoted mercury tube, thermostatic means, a scale associated with, so as to be turned by, said thermostatic means, an arm adjustable relative to and adapted to engage said switch, an adjustable and operative connection between said arm and thermostatic means and including a double acting ball clutch, and a setting pointer for adjusting said clutch and cooperatingfwith said scale;

6. In a thermostatically operated switch, a switch having a pivoted element, thermostatic means, a shaft adapted to be turned by said thermostatic means, a scale carried by said shaft so as to turn therewith, a fixed pointer cooperating with said scale, an operating member adapted to turn with said shaft and adjustable relative to said switch, an adjustable double acting. clutch between said operating member and shaft, and a setting member adapted to turn with said shaft and adjustable relative thereto, said setting member having a pointer cooperating with said scale.

7. In a thermostatically operated switch, a switch comprising a pivoted mercury tube, thermostatic means, a shaft adapted to be turned by said thermostatic means, a scale carried by said shaft, a iixed pointer cooperating with said scale an arm adapted to turn with said shaft and adjustable relative to said switch; a clutch between said arm and shaft and including a driving `clutch member xed to the shaft, a driven clutch member to which said arm is xed, and a pair of balls between said clutch members, one of said balls constituting a driving connection when the shaft is turned in one direction and the other of said balls constituting a driving connection when the shaft is turned in the opposite direction, and a setting member normally turnable with said shaft and having a pointer cooperating with said scale, said setting member having fingers respectfully cooperating with said balls for moving the same from engaged position when the setting member is turned relative to the shaft.

8. In a thermostatically switch, a thermostatic element, a scale operable by the element, a switch closer, adjustable connecting means between the scale and the switch closer for operating the latter at a predetermined time to close the switch, and an adjusting device adjustably associated with said scale to move therewith and disposed for engagement with said connectingmeans for adjusting the same for operation relatively to the scale.

'9. In a thermostatically operated switch, a switch, a thermostatic element, a shaft connected to the element to be turned thereby, a. scale xed to the shaft, a driving element carried by the scale, a second driving element having a switch closer thereon in the path of the switch, adjustable connecting means between the driving elements, and an adjusting device for the connecting means adjustably mounted on the shaft and movable therewith and having a pointer cooperative with the scale for determining the temperature at which said connecting means may operate.

THOMAS HEWES, W. ARTHUR COUNTRYMAN, JR., Administrators of the Estate of Gerald W. Hart,

Deceased.

operated switch, a 

